Cataract patients in a defined Swedish population 1986-1990

Abstract: There has been a striking increase in the number of cataract operations in the referral region of the Lund Health Care District during 1986 through 1990, in 1990 reaching 3.6 per 1000 inhabitants. Different preoperative, intraoperative and postoperative variables and observations were registered and analysed for 5878 consecutive cataract cases operated in the period studied. Women predominate in the material and despite the increased number of operations during the period studied there was no drop in patient age. Young patients and diabetic patients show an increased standardised mortality ratio (SMR) compared to the normal population. Of the population, 78% had a preoperative astigmatism of <1.5 diopters. The amount of astigmatism was found to deviate more from the normal both in large and in small eyes. A second degree polynomial model was found to give the best description of the relation between axial length and keratometric powers. A cataract patient with glaucoma and operated on by an inexperienced surgeon runs a significantly increased risk for complications at surgery, as indicated by capsule or zonule rupture. At two years after cataract surgery we found the risk for retinal detachment to be 0.18%. The relative risk for detachment was found to be 4.9 after a YAG-laser capsulotomy. It changed by a factor of 1.3 with an increase in the axial length by one unit (=1 mm) and with 0.94 for each added patient age year. Besides age, five variables significantly influenced the risk of having postoperative YAG laser treatment. They were gender, iris sphincterotomy, operation date and the community from which the patient came from. After about four to five years, the percentage of patients not having had a YAG laser capsulotomy was reduced to around 50% for women and 60% for men. The most important predisposing factors for an early large with the-rule-astigmatism or rapid changes in the postoperative astigmatism were large preoperative with-the-rule astigmatism (polar value), young age, low preoperative intraocular pressure, if an ECCE were chosen as the extraction type, anterior (corneal) location of the incision at surgery, and, finally, the surgeon.